I've always felt that (with respect to desktop work specifically), the reason we're in the web-app world we are today was in part due to the stagnation of window management in the 90's - 00's Windows era. Tabbed browsing for web browsers was created pretty much to overcome having a gluttonous and unusable taskbar after opening just a few applications. From then on, I feel users were primed to want an alternative, which web apps ultimately gave.

Further, to talk about the speed hit associated with web apps, laptops and desktops are still primarily sold with old-school hard disk drives instead of solid state (unless you pay a big premium, which most people don't want to do). Frankly, opening a native application on an older machine (and for most users, one which hasn't been defragmented even once) was an awful waste of time. But Google Docs? Heck, you didn't even need to be on the same computer to access those files. Not to mention trying to update these apps being a massive chore on these slow machines. Heck, most people didn't ever update their browsers until Mozilla and Google imposed it upon users.

While I'd like a world where the browser is not an abstraction layer for an OS, I do recognize that these web apps exist for a reason.